1. Field of the Invention
This invention relates to a capstan for use in a magnetic tape transport system and more particularly to a capstan which has low mass, a low moment of inertia-to-diameter ratio, and which is inexpensive to manufacture compared to other capstans having similar characteristics.
2. Description of the Prior Art
In the computer industry it is important to accelerate magnetic tape from a stop position to a preselected rate, such as 200 inches per second, in a very short time. In like manner, when the tape is running, it is desired to stop the tape in an exceedingly short period of time. In some instances the tape must be started in one direction and very quickly thereafter stopped and reversed and moved in the opposite direction. For a given tape speed and start and stop distances, a power required to accelerate the capstan is proportional to the square of the mass moment of inertia. It can be seen that providing a capstan of very low mass and very low moment of inertia-to-diameter is exceedingly important. Others have provided capstans having these desired characteristics. Reference may be had to U.S. Pat. No. 4,065,044 entitled "CAPSTAN", issued Dec. 27, 1977. This patent provides a type of capstan wherein the goal is the same as in the present invention, that is, a capstan for driving a magnetic tape wherein the capstan has a low mass and a low moment of intertia-to-diameter ratio. References cited in this patent may also be resorted to as background information for the type of product to which the present invention is directed.
Briefly stated, an object of the present invention is to provide a capstan for use in magnetic tape transport systems in which the capstan has a low mass and a low inertia-to-diameter ratio and particularly wherein such goals are achieved in a new way facilitating the construction of the capstan much more expeditiously and economically than prior known construction methods.